Electrical therapeutic device



Sept. 12, 1950 F. J. HART 2,522,269

ELECTRICAL THERAPEUTIC DEVICE Filed June 30, 1948 35 9 3o %43 B H 33 k M34 40 I7 /8 6 /4 JL-Zi i INVENTOR. Fred J. Har7 MGGKWK,

Patented Sept. 1950 Fred J. Hart, Salinas, Calif.

Application June 30, 1948, Serial No. 36,221

1 Claim.

My invention relates to improvements in electrical apparatus forproducing interrupted alternating magnetic fields for therapeutic uses.

One object is the provision of an electromagnet which, with analternating current, is adapted to set up electrical currents in humantissues for helping to relieve inflammatory conditions.

Another object is the provision of an electromaget made up of a core ofmagnetic material and a coil winding on said core with means forautomatically making and breaking an electrical current in a recess insaid core so that the current will be made and broken in the magneticfield of said electromagnet.

Another object is the provision of simple and efiicient means foraccomplishing this end.

Other objects will be apparent from the following description andaccompanying drawing, in which:

Figure 1 is a view showing an electromagnet in section and an electricalcircuit with the latter mostly in diagram, and

Figure 2 is a diagrammatical view of the electrical circuit.

Referring more particularly to the drawing, the electromagnet of mydevice preferably has a magnet core made up of a large rear portion 5and a cylindrical hub portion 6. The magnet may be of any other desiredshapes. A 0011 of wire 1 is wound on the hub portion 6 and formed to fitthe front surface of the enlarged portion 5 of the core. The ends 8 and3 of the coil 1 are led to the middle posts l and II of a double poledouble throw switch. When the blades} l2 and I3 are connected with thepoles l4 and I5 current supply wires l6 and I1 furnish uninterruptedcurrent to coil 1. An "off and on switch l8 controls the supply ofalternating current electricity to the device.

A thermal switch is mounted on a. nonconductor block IS in a recess 20in the front end of the core part 6. The arrangement is such that whenthe current is chopped with the thermal switch mounted on the undersideof the block iii the spark will occur in an electromagnetic field.

The thermal switch consists of a bimetal bar 2| adapted to be bent byheat to open switch points 22 and 23. A resistance coil 24 is wound onsaid bar 2| with one end secured to the bar 2|. The

latter bar has one end secured by rivet 25 to block IS. The bar 2| isarranged to hold points 22 and 23 together normally. Current in the coil24 heats the bar 2| and moves point 22 away from point 23. When saidpoints separate, the current breaks and coil 24 and bar 2| cool again torepeat the cycle.

Switch point 23 is secured by a rivet 28 to block I9 and connected bywire 21 to switch post i4. The other end of coil 24 is secured to block|9 by rivet 28 and connected through wire 29 to switch post 30.

Rivet 25 is connected by a wire 3| to one end of the primary coil 32 ofan air core transformer. The other end of coil 32 is connected by a wire33' to switch point 34.

A condenser 35 is connected between ends of the primary coil 92 andsecondary coil 36. The other end of the secondary coil 36 is connectedby wire 31 to a treatment plate 38. The latter is mounted on the frontface of a front cover 39 which may be of Bakelite or other non-magneticmaterial.

Front cover 39 is secured at its periphery to the front edge of the rearbrass or other metal casing 49 by rivets 4| or their equivalents. Themagnet part 5 is secured to the rear casing by brackets, one of which isshown at 42. The casing may be provided with openings 43 for thecirculation of air. Suitable insulation material 44 is placed betweenthecoil and the core parts 5 and 6.

In operation, when switch :bladesare thrown over to contact with posts 4and |5, the coil acts continuously and must be operated on alternatingcurrent.

When the switch blades l2 and i3 are thrown over to engage posts 30 and34, current travels from wire I 6 to wire 21 and through points 22 and23 as long as they are closed. While the switch points are closed theheavy part of the current travels over bimetal bar 2| and wire 3| toprimary coil 32, then to post 34, blade l2 and over wir 8 to coil 1. Thecurrent returns over wire 9 to supply wire H.

A small part of the current branches ofi through heater coil 24 to heatand bend the bimetal bar 2| to open the points. While the points areclosed, current returns from coil 24 over wire 29 to switch post 30,then blade l3 to supply wire l1.

An important feature is the electromagnet with one large end and onesmall one to provide a mor concentrated flux at the small end. Then,cutting the supply current in the small end and in the concentratedfield.

I claim:

In an electrical therapeutic device, the combination of an electromagnethaving a coil and a core, said core having a cylindrical portiondisposed in said coil and an enlarged portion against one end of saidcoil, said cylindrical core portion having a central recess in its outerend adapted to provide a relatively weak magnetic field over the recessand a strong magnetic field at the eriphery of said end, and anautomatically operi5 ated switch in said recess and operativelyconnected to said coil.

FRED J. HART.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Pignolet Dec. 24, 1940

